Bench-clamp.



H. R. MITCHELL & I. L. SLOAN.

BENCH CLAMP.

APPLICATION FILED MAY 13,1912.

1,056,818. r Patented Mar.25,1913.

J4? 1Z0 E24 Witnses f lnventors by I r I I Attorneys UNITED STATESPATENT OFFICE.

HARRY R. MITCHELL AND IRA L. SLOAN, OF SEATTLE, WASHINGTON.

BENCH-CLAMP.

Specification of Letters Patent.

Patented Mar. 25, 1913.

The present invention relates to improvements in bench clamps,.theprimary object of the present invention being the provision of a benchclamp composed primarily of two members, including the tail screw and acasing provided with means, whereby the same is readily placed inposition by bearing down upon the same to force engaging ron s into theuo er surface of a car enters bench and carrying means for co-actionwith the tail screw to clamp therebetween the piece of material to beoperated upon.

A further object of the present invention is a novel arrangement ofadjustable clamping means carried by one of the members of a benchclamp, the same being so constructed as to be readily adjusted and heldat such adjustment to clamp the material operated upon in the desiredposition, and of such a height as to readily permit of the operationupon a thin piece of material without the clamp protruding or projectingin the path of a plane when planing a piece of board or material, theclamping member being furtherprovided with means for automaticallyreleasing the screw when it is desired to remove the work from theclamp.

With the foregoing and other objects in View which will appear as thedescription proceeds, the invention resides in the combination andarrangement of parts and in the details of construction hereinafterdescribed and claimed, it being understood that changes in the preciseembodiment of the invention herein disclosed can be made within thescope of what is claimed without departing from the spirit of theinvention.

In the drawingsFigure 1 is a view showing the tail piece in plan whilethe clamping member has its top plate removed to show the interiorconstruction. Fig. 2 is a perspective view of the tail piece andclamping member in operable relation. Fig. 3 is a view taken from thelever side of the removable clamping member. Fig. 1 is a section takenon line lt of Fig. 1.

Referring to the drawings, the numeral 1 designates the work bench, and2 the material to be operated upon. The stem 8 is mounted for verticallysliding movement in the frame 4 which is connected as shown in Fig. l toone end of the bench, with the upper plate of the frame below the upperplane of the work bench. A spring 5 is disposed upon the stem 3 betweenand within the frame 4 and normally exerts a tension to hold the stem 3upwardly so that the tail piece 6 may be disposed at various levelsabove the surface or plane of the work bench, according to the thicknessof the material 2 operated upon. This tail piece 6 is provided with theserrated work engaging end 7 and with the V-shaped end 8, the stem 3being so disposed that the tail piece may be rotated to place theserrated portion 7 or the V-shaped endin engagement with the material.

" The removable member 9 of the bench clamp consists of the lower plate10 and the upper plate 11, either one of said plates being provided withthe'depending edges or flanges 12, which when the plates are placed inregistration and are held together by means of screws 13, provides acasing for the operating mechanism carried by the re movable member ofthe bench clamp.

In order that the removable member may be detachably secured to theupper surface of the work bench, a plurality of prongs or tangs 14 arecut from the bottom section 10 of the casing and are so positioned thatthe operator in placing the clamping member 9 in place bears down uponthe same to project the prongs or tangs within the upper surface of thebench. .By this means any length of material may be operated upon andproperly clamped between the tail piece 6 and the removable member 9.

Mounted for sliding movement within the casing is the work engaging bar15, which is provided with the toothed outer end 16 that normallyprojects without the casing to be placed in engagement with the material2. This bar 15, is provided with the rack teeth 17 which are inengagement at all times with the teeth 18 of the segment 19, thissegment 19 being pivoted or fulcrumed upon the pivot or screw 13 andhaving its operating lever or handle 20 so disposed as to normallyproject eXteriorly of the casing at one side thereof in ready access tothe operator.

A lug 21 is formed integral with the segment 19 and has connected at 22one terminal of the coiled spring 23 which is disposed around the pin 24and has its other end 25 connected beyond the fulcrum 26 of the barlocking pawl 27, which has its releasing end projecting exteriorly ofthe casing, with the single toothed end 28 disposed to engage the rackteeth 29 of the bar 15. Thus two series of teeth are formed upon thesame edge of the bar, and a single spring is employed to control boththe lever 20 and the locking pawl 27.

From the foregoing description, taken in connection with the drawings,the operation of the present bench clamp is readily understood butbriefly stated it is as follows: The material 2, that is to be operatedupon, is engaged by the tail piece 6, said tail piece 6 being compressedso that the upper surface thereof will not project above the uppersurface of the material 2. The removable member 9 is then positionedupon the work bench, the operator forcing the casing downwardly so thatthe tangs let will enter the upper surface of the work bench and thusbrace the member 9 against the action of the bar 15, when the same ispropelled or projected toward the material 2 by the actuating segment18, the lever 20 being moved to the right, as viewed in Fig. 2. Thisaction will extend the spring 23 so that the normal tension or tendencyof the segment 19 is to retract the bar 15. In order to lock the bar inthe projected position while engaging the material 2, the locking pawl27 is manipulated so that the tooth 28 thereof will engage the propertooth 29 of the bar 15 and thus lock the parts in the desired work engaging position. It will thus be seen that the tension of the spring 23will be to hold the tooth 28 of the locking pawl into engagement withthe rack teeth 29 of the bar 15, while the segment 19 will be pulledupon to automatically retract the bar 15 when the tooth 28 of the pawl27 is released from the teeth 29 of the bar 15.

What is claimed is:

1. In a bench clamp, having two members, one being a tail member and theother a member between which and the tail member the work is placed,said last member constituting a casing, a bar mounted for reciprocatorymovement within the casing and disposed to be projected to engage thework, a manually operated means disposed within the casing and inoperable relation exteriorly thereof to project the bar into workengaging position, means for locking the bar in projected position, anda single spring connected to said manually operated means and thelocking means for retracting the bar when the locking means is released.

2. In a bench clamp, having two members, one being a tail member and theother a member between which and the tail member the work is placed,said last member constituting a casing, a bar mounted for reciprocatorymovement within the casing, and disposed to be projected to engage thework, a manually operated means disposed within the casing and inoperable relation exteriorly thereof to project the bar into workengaging position, a pawl pivoted within the casing and having a handleprojecting exteriorly thereof, the inner end of said pawl being disposedto engage the bar to lock the same in projected position, and a singlespring connected to the operating means and the pawl for holding thepawl in locking position and to automatically retract the bar whenreleased from engagement with the pawl.

3. A bench clamp, having two members, one a tail member and the other acooperating member and between which members the work is to be placed,said last member constituting a casing, a bar mounted for reciprocatorymovement within the casing and disposed to-be projected to engage thework, a lever mounted in the casing and operable exteriorly thereof,said lever and bar being provided with co-acting means whereby theoperation of the lever projects the bar, a manually released lockingpawl disposed to engage the bar and lock the same in projected position,and a single spring connected to the lever and pawl for holding the pawlin locked position and for automatically returning the bar when releasedby the pawl.

4. A bench clamp, including a member constituting a casing provided witha plurality of bench engaging prongs, a work engaging bar slidablymounted within the easing, said bar being provided with two separatedseries of teeth upon the same side thereof within the casing, a leverpivoted within the casing and operable exteriorly 'ment engaging oneseries of the teeth of the bar, a pawl pivoted within the casing and asour own, we have hereto aflixed our signaprovided with a handleprojecting extetures in the presence of two witnesses. riorly of thecasing said pawl being dis- HARRY R. MITCHELL. posed to engage the otherseries of teeth of IRA L. SLO'AN. 5 the bar to lock the bar in projectedposi Witnesses as to signature of Harry R.

tion and a single spring connected to the Mitchell: pawl and segment forlooking the pawl in WM. MAXWELL, tooth engaging position and forautomati- F. E. WHITE. eally returning the bar when released fromWVitnesses as to signature of Ira L. Sloan: 10 engagement with the pawl.JAMES O. CULL,

In testimony that we claim the foregoing JEROME LEWIS.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington. D. C.

